An OLED (Organic Light-Emitting Diode), due to its various advantages such as all-solid-state structure, high brightness, full angle of view, fast response, wide range of operating temperature, attainability of flexible display and the like, so far has become a next generation display technology having high competitiveness and prospects for development. An OLED device uses an organic light-emitting material and a cathode material particularly sensitive to water and oxygen, hence excessively high humidity or excessively high content of oxygen will influence the lifetime of the OLED device, and in order to effectively cut off the influence of water and oxygen to the OLED device, it is required to encapsulate the OLED device.